Pryce, who already had two children from a previous marriage and two with Huhne, said of the abortion: "It was all booked and I was meant to go that morning.

"I woke up and knew how I had felt about the previous one and knew I couldn't do it.

"I just couldn't bring myself to do it and I had learned from the previous one."

Asked how Huhne pressured her to have the first abortion, Pryce said: "He didn't say, 'I will divorce you if you carry on', but it was obvious that the environment in the house would be pretty bad if I carried on and that of course would simply have added to the strain."

She told the court: "Mr Huhne was somebody who wanted to achieve his aims and nothing could come in his way of doing so.

"His aims, of course, were mainly political or financial, depending on the period in his life, so that was absolutely at the top of his agenda.

"So whenever it came to anything that might affect either his political career or many financial stuff, he would certainly win."

The economist, who is said to have leaked the story about the points to the press in a bid to "nail" her husband after he left her for PR adviser Carina Trimingham, said she "wanted to turn the clock back" when the story hit the headlines.

Pryce, 60, revealed the scandal to Sunday Times political editor Isabel Oakeshott in March 2011 and the pair agreed a way of producing the story aimed to protect Pryce from prosecution.

The court heard that the economist had already spoken to the Mail on Sunday about the story some six months before, telling them Huhne had apparently passed points to constituency aide Jo White.

But they did not run the story - which turned out to be untrue - and prosecutor Andrew Edis QC suggested that because it was a "dead duck", Pryce went to Ms Oakeshott.

Emails passed between Pryce and Ms Oakeshott, as well as between Pryce and the Mail on Sunday, as both newspapers pursued the story.

Pryce was helped by a friend, lawyer and part-time judge Constance Briscoe, in her dealings with the Mail on Sunday, the court heard.

The economist admitted speaking to journalists about throwing Huhne's clothes out of the front door after he took Ms Trimingham to meet the Queen at Windsor Castle in late 2010.

But Pryce said that when the points-swapping story first appeared on May 8 2011, she was shocked and horrified.

"In many ways I just wanted to turn the clock back and not have anything to do with it.

"Mostly I felt I wished really to have nothing to do with it if I could and felt quite ashamed and upset."

She did not deal with the Sunday Times after that, but carried on speaking to the Mail on Sunday.

Pryce said she had not behaved rationally, adding: "I was not probably thinking straight at the time, there's no doubt about it.

"It was a very, very tough time for me and also for the rest of my family and I did things which I am not proud of."

She said she wanted to expose Huhne's wrongdoing, not ruin his career, adding: "If I really wanted to inflict fatal damage on him I could have done something very, very different."

Pryce added: "If I had wanted to ruin my husband at the time I could have thought of lots of other things to expose publicly."

The court heard glowing testimonials about Pryce from several high-profile figures, including former head of MI6 John Scarlett, former senior civil servant John Gieve, and Baron Stern of Brentford.

Mr Edis said the only reason Pryce had described Huhne standing in the hallway with a pen was because her defence of marital coercion requires a husband to be physically present.

But she said the moment was "one of my strongest memories of this whole sad affair".

Mr Edis told her: "The reality is Ms Pryce, of all the women who are pressured by their husband, you were in the best possible position to resist and do the right thing."